1. Field of the Invention
This invention relates to a joint inspection apparatus for automatically inspecting an overlap of tape edge portions one upon the other at a tape joint in the case where long tapes are joined together. This invention particularly relates to a joint inspection apparatus for detecting the presence or absence of an overlap of edge portions of, for example, a leader tape and a magnetic tape one upon the other, which overlap may arise in the case where the leader tape and the magnetic tape are joined together by use of a joining tape for obtaining a video tape, an audio tape or the like.
2. Description of the Prior Art
In the course of making video tape cassettes or audio tape cassettes, a leader tape (or a trailer tape) and a magnetic tape are joined together by use of a joining tape, and the presence or absence of an overlap of edge portions of the leader tape and the magnetic tape one upon the other at the joint area has heretofore been judged by visual inspection by the operators.
However, with the visual inspection, criteria of judgment differ among the operators, and defective products may be missed due to fatigue of the operators. Therefore, it is not always possible to make the quality of the products uniform. Also, personnel expenses for the operators cause the product cost to increase, and the production speed is decreased by the presence of the artificial process in the production processes.